A battery resistant to potential-induced polarization decay and its preparation process

Abstract

The invention relates to the technical field of photovoltaic cell assemblies, in particular to a cell resistant to potential-induced polarization attenuation and a preparation process thereof; the cell comprises a photovoltaic cell substrate, the upper surface or the lower surface of which is coated with a layer of coating resistant to potential-induced polarization attenuation, the photovoltaic cell comprises an N-type single-sided cell, an N-type bifacial cell, a P-type bifacial cell and an IBC cell, the photovoltaic cell is an N-type single-sided cell or an N-type bifacial cell, and the coating is coated on the front of the N-type single-sided cell or the N-type bifacial cell; in the invention, a layer of coating resistant to potential-induced polarization attenuation is coated on the upper surface or the lower surface of the photovoltaic cell substrate, and functional additives such as charge neutralization and leakage are added to the coating to remove polarization charges generated on the surface of the cell, thereby giving the cell the function of resisting polarization attenuation.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic cell components, in particular to a cell resistant to potential-induced polarization attenuation and a preparation process thereof. Background Art

[0002] According to the 2020 International Photovoltaic Technology Roadmap Forecast (ITRPV), the market share of bifacial cells will exceed 50% by 2026. Due to the special cell structure of bifacial cells, when the components are under negative bias, 85°C temperature, and 85% humidity, a layer of positive charge will be generated on the surface of the cell, which is called polarization charge, destroying the passivation effect of the cell, causing the minority carriers to recombine with the majority carriers, resulting in current and voltage loss, thereby leading to power loss (PID attenuation).

[0003] The PID attenuation caused by this polarization is currently mainly solved by encapsulating film at the component end. The current mass production plan of encapsulating film is mainly to add multifunctional acrylates or acrylamides with double bonds to POE or EVA / POE composite film, such as the one mentioned in patent CN109810639A, using one or more of N,N'-methylenebisacrylamide, hydroxymethyl acrylamide, hydroxyethyl acrylamide, hydroxyethyl acrylamide or N,N-dimethyl acrylamide. Multifunctional acrylate or methacrylate additives mentioned in CN109337599A. Ethoxylated pentaerythritol triacrylate, propoxylated neopentyl glycol diacrylate, and ethoxylated trimethylolpropane triacrylate mentioned in CN110964447A patent.

[0004] However, these additives have relatively large polarity, while POE has small polarity, so their compatibility is poor and they are easy to precipitate at low temperatures, resulting in slippage and bubbles during the use of the film. Using these additives in EVA film still cannot meet the PID requirements of bifacial battery modules. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a battery with strong anti-PID-p ability and anti-potential induced polarization decay, by coating a layer of anti-PID-p functional layer on the upper surface or the lower surface of the battery, thereby improving the anti-PID-p ability of the battery and the components made of the battery.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A cell resistant to potential-induced polarization attenuation comprises a photovoltaic cell substrate, wherein the upper surface or the lower surface of the photovoltaic cell substrate is coated with a layer of coating resistant to potential-induced polarization attenuation.

[0008] Furthermore, the photovoltaic cells include N-type monofacial cells, N-type bifacial cells, P-type bifacial cells and IBC cells.

[0009] Furthermore, the photovoltaic cell is an N-type monofacial cell or an N-type bifacial cell, and the coating is coated on the front side of the N-type monofacial cell or the N-type bifacial cell.

[0010] Furthermore, the photovoltaic cell is a P-type bifacial cell, and the coating is coated on the back side of the P-type bifacial cell.

[0011] Furthermore, the coating has a thickness of 0.001 to 100 μm.

[0012] Furthermore, the material of the functional coating is an emulsion mixture, the main body of the emulsion is one or more compositions of aqueous or oily ethylene and vinyl acetate copolymer, polyurethane, acrylate, epoxy resin, polyester, polycarbonate, polyether emulsion, and the emulsion contains anti-PID-p functional additives.

[0013] Furthermore, the material of the functional coating is a hot melt adhesive mixture, the main body of the hot melt adhesive is one or more combinations of hot melt adhesives such as polyethylene and its copolymers, ethylene-α-olefin copolymers, polypropylene, polybutylene, polyvinyl chloride, polyesteramide, polyurethane, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-ethylene·butylene-styrene copolymers, styrene-ethylene-propylene-styrene copolymers, and the hot melt adhesive is added with a functional additive containing anti-PID-p.

[0014] Furthermore, the functional additive is a combination of one or more substances including multifunctional acrylates or acrylamides with double bonds, silane coupling agents with double bonds and methoxy, ethoxy or propoxy groups, N-type semiconductor materials, polyolefin epoxy block dispersions based on polyol systems, copolymers containing polyether blocks, methacrylate polymers containing quaternary ammonium salts, sodium polystyrene sulfonate, carboxytrimethylamine ethyl lactone graft copolymers, polymers with alternating carbon-carbon single bonds and double bonds, metal phthalocyanine polymers, ferrocene-type metal organic polymers, and polyelectrolytes.

[0015] Another object of the present invention is to overcome the deficiencies in the prior art and provide a preparation process for a battery resistant to potential induced polarization decay. The preparation process covers the upper or lower surface of the battery with a functional layer having anti-PID-p function by spraying, scraping, rolling, thermal transfer, optical transfer, etc., depending on the type of battery, thereby improving the anti-PID-p ability of the battery and the components made of the battery, and the process is simple and the production cost is low.

[0016] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0017] A preparation process for a battery resistant to potential induced polarization attenuation, wherein the coating is applied to the surface of a battery that has not been welded or has been welded in single or series by spraying, scraping, rolling, or thermal transfer or optical transfer.

[0018] Furthermore, during the coating process, when the coating is applied to the unwelded battery surface, the welding position of the battery cell is avoided.

[0019] The beneficial effects of the technical solution of the present invention are:

[0020] In the present invention, a layer of anti-potential induced polarization attenuation coating is coated on the upper surface or the lower surface of the photovoltaic cell substrate, and functional additives such as charge neutralization and leakage are added to the coating to remove the polarization charge generated on the surface of the cell, thereby giving the cell the function of anti-polarization attenuation.

[0021] The preparation process of the battery resistant to potential induced polarization decay in the present invention is simple, has high production efficiency and low cost, and the prepared battery resistant to potential induced polarization decay has strong ability to resist PID-p. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0023] Figure 1 Schematic diagram of the layer structure of the battery resistant to potential induced polarization decay in the present invention.

[0024] Figure 2 Schematic diagram of the coating area on the surface of the battery where welding is not completed in the present invention.

[0025] In the figure: 1 photovoltaic cell substrate, 2 anti-potential induced polarization attenuation coating, 3 position to be welded. DETAILED DESCRIPTION

[0026] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention. The present invention is described in detail using structural schematic diagrams, etc. The schematic diagrams are only examples, and should not limit the scope of protection of the present invention. In addition, in actual production, a three-dimensional space of length, width and depth should be included.

[0027] See also Figure 1A cell resistant to potential-induced polarization attenuation comprises a crystalline silicon photovoltaic cell substrate 1, and a layer of anti-potential-induced polarization attenuation coating 2 is coated on the upper or lower surface of the photovoltaic cell substrate 1. When the crystalline silicon photovoltaic cell or the photovoltaic module made of the cell is subjected to negative bias or positive bias, the cell surface will produce polarization induced by potential, resulting in a large power attenuation. Therefore, in the present invention, a layer of anti-potential-induced polarization attenuation coating 2 is coated on the upper or lower surface of the photovoltaic cell substrate 1, and functional additives such as charge neutralization and leakage are added to the coating to remove the polarization charge generated on the cell surface, thereby giving the cell the function of anti-polarization attenuation.

[0028] The crystalline silicon photovoltaic cell in the present invention includes an N-type monofacial cell, an N-type bifacial cell, a P-type bifacial cell and an IBC cell. When the photovoltaic cell is an N-type monofacial cell or an N-type bifacial cell, the coating is applied on the front of the N-type monofacial cell or the N-type bifacial cell. When the photovoltaic cell is a P-type bifacial cell, the coating is applied on the back of the P-type bifacial cell.

[0029] The thickness of the coating in the present invention is 0.001-100 μm, preferably 15-100 μm.

[0030] The material of the functional coating in the present invention is an emulsion mixture, the main body of the emulsion is one or more compositions of aqueous or oily ethylene and vinyl acetate copolymer, polyurethane, acrylate, epoxy resin, polyester, polycarbonate, polyether emulsion, and functional additives containing anti-PID-p are added to the emulsion.

[0031] The material of the functional coating in the present invention is a hot melt adhesive mixture, the main body of the hot melt adhesive is one or more combinations of hot melt adhesives such as polyethylene and its copolymers, ethylene-α-olefin copolymers, polypropylene, polybutylene, polyvinyl chloride, polyesteramide, polyurethane, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-ethylene·butylene-styrene copolymers, and styrene-ethylene-propylene-styrene copolymers; the hot melt adhesive is added with functional additives containing anti-PID-p.

[0032] The functional additive in the present invention is a combination of one or more substances including multifunctional acrylate or acrylamide with double bonds, a silane coupling agent with double bonds and containing methoxy, ethoxy or propoxy groups, an N-type semiconductor material, a polyolefin epoxy block dispersion based on a polyol system, a copolymer containing a polyether block, a methacrylate polymer containing a quaternary ammonium salt, sodium polystyrene sulfonate, a carboxytrimethylamine ethyl lactone graft copolymer, a polymer with alternating carbon-carbon single bonds and double bonds, a metal phthalocyanine polymer, a ferrocene-type metal organic polymer, and a polyelectrolyte.

[0033] In the preparation process of the battery resistant to potential induced polarization attenuation of the present invention, the coating is applied to the surface of the battery that is not welded or has been welded in single welding and series welding by spraying, scraping, rolling, or thermal transfer or optical transfer. When the coating is applied to the surface of the battery that is not welded, avoid the welding position of the battery cell.

[0034] Example 1

[0035] The battery cell provided in this embodiment is a 166*166mm P-type bifacial battery. The coating of the battery cell is ethylene-vinyl acetate hot melt adhesive, the weight of which is 100 parts, and the contents of other additives are as follows: 6 parts by weight of multifunctional acrylate silane with double bonds, 0.25 parts by weight of vinyl triethoxy silane, 0.04 parts by weight of 2,2'-methylenebis(6-(2H-benzotriazole-2-yl)-6-dodecyl-4-methylphenol, and 0.05 parts by weight of pentaerythritol tetrakis[β-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

[0036] After the coating materials are stirred and blended, they are heated to 150° C. and sprayed onto the back of the battery cell by a sprayer. When spraying, the battery cell welding area 3 needs to be avoided. The coating thickness is 100 μm.

[0037] Example 2

[0038] The battery cell provided in this embodiment is an N-type bifacial battery of 158.75*158.75mm. The coating of the battery cell is a copolymer of ethylene and acrylic acid, and its weight is 100 parts. The content of other additives is as follows: 8 parts by weight of polyether polyol with ethylene oxide end block, 0.15 parts by weight of vinyl trimethoxy silane, 0.03 parts by weight of 2,2-dihydroxy-4-methoxy benzophenone, and 0.04 parts by weight of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate.

[0039] After the coating materials are stirred and blended, a film with a thickness of 60 μm is formed by an extruder, and then cut into the size of a battery cell. After the battery cell is welded, the film is transferred to the front of the battery cell at 150° C.

[0040] Example 3

[0041] The battery cell provided in this embodiment is an N-type single-sided battery with a size of 161.75*161.75mm. The coating is an aqueous polyurethane emulsion with a solid content of 45%. The weight is 100 parts. The contents of other additives are as follows: 8 parts by weight of polymethacrylate containing quaternary ammonium salt, 0.3 parts by weight of γ-methacryloxypropyltrimethoxysilane, 0.02 parts by weight of γ-aminopropyltriethoxysilane, and 0.03 parts by weight of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate.

[0042] After the emulsion is stirred evenly, it is sprayed onto the front of the battery cell. When spraying, avoid the battery cell welding area 3, and then dry at room temperature. The film thickness after drying is 20 μm.

[0043] Example 4

[0044] The battery cell provided in this embodiment is a 210*210mm P-type single-sided battery. The coating is an aqueous ethylene-vinyl acetate emulsion with a solid content of 55%. The weight is 100 parts. The contents of other additives are as follows: 10 parts by weight of polyether polyol end-blocked with ethylene oxide, 1 part by weight of 3-isocyanate propyl trimethoxysilane, 0.025 parts by weight of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and 0.035 parts by weight of triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0045] After the emulsion is evenly mixed, it is printed on the surface of the battery cell by screen printing, while avoiding the battery cell welding position 3. It is then dried at about 60°C, and the thickness of the dried film is 15 μm.

[0046] The cells described in Examples 1-4 were packaged with conventional EVA to form double-sided double-glass modules, and then subjected to a voltage of -1500V for 96 hours at 85°C and 85% humidity for PID testing. At the same time, cells without surface treatment were added to form modules for comparison. Specific test data are shown in Table 1.

[0047] Table 1

[0048] Experimental Project Example 1 Example 2 Example 3 Example 4 Comparative Example Test standard or method PID post-decay 3.7％ 1.6％ 2.3％ 1.0％ 17％ IEC62804-2015

[0049] With the above-mentioned ideal embodiments of the present invention as inspiration, through the above-mentioned description, relevant staff can make various changes and modifications without departing from the technical idea of ​​the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A battery resistant to potential induced polarization decay, characterized in that: It comprises a photovoltaic cell substrate, wherein the upper surface or the lower surface of the photovoltaic cell substrate is coated with a layer of anti-potential induced polarization attenuation coating; The material of the anti-potential induced polarization attenuation coating is an emulsion mixture, the main body of the emulsion is one or more compositions of water-based or oily ethylene and vinyl acetate copolymer, polyurethane, acrylate, epoxy resin, polyester, polycarbonate, polyether emulsion, and the emulsion is added with a functional additive containing anti-PID-p; or The material of the anti-potential induced polarization attenuation coating is a hot melt adhesive mixture, the main body of the hot melt adhesive is one or more combinations of polyethylene and its copolymers, ethylene-α-olefin copolymers, polypropylene, polybutylene, polyvinyl chloride, polyester amide, polyurethane, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-ethylene·butylene-styrene copolymers, and styrene-ethylene-propylene-styrene copolymer hot melt adhesives, and the hot melt adhesive is added with a functional additive containing anti-PID-p; The anti-PID-p functional additive is a combination of one or more substances including multifunctional acrylate or acrylamide with double bonds, a silane coupling agent with double bonds and methoxy, ethoxy or propoxy groups, an N-type semiconductor material, a polyolefin epoxy block dispersion based on a polyol system, a copolymer containing a polyether block, a methacrylate polymer containing a quaternary ammonium salt, sodium polystyrene sulfonate, a carboxytrimethylamine ethyl lactone graft copolymer, a polymer with alternating carbon-carbon single bonds and double bonds, a metal phthalocyanine polymer, a ferrocene-type metal organic polymer, and a polyelectrolyte.

2. A battery resistant to potential induced polarization decay according to claim 1, characterized in that: The photovoltaic cells include N-type monofacial cells, N-type bifacial cells, P-type bifacial cells and IBC cells.

3. A battery resistant to potential induced polarization decay according to claim 2, characterized in that: The photovoltaic cell is an N-type monofacial cell or an N-type bifacial cell, and the coating is coated on the front side of the N-type monofacial cell or the N-type bifacial cell.

4. A battery resistant to potential induced polarization decay according to claim 2, characterized in that: The photovoltaic cell is a P-type bifacial cell, and the coating is coated on the back side of the P-type bifacial cell.

5. A battery resistant to potential induced polarization decay according to claim 1, characterized in that: The coating has a thickness of 0.001-100 μm.

6. A process for preparing a battery resistant to potential induced polarization decay according to any one of claims 1 to 5, characterized in that: The anti-potential induced polarization attenuation coating is applied to the surface of the battery that has not been welded or has been welded in single or series by spraying, scraping, rolling, or thermal transfer or optical transfer.

7. The process for preparing a battery resistant to potential induced polarization decay according to claim 6, characterized in that: During the coating process of the anti-potential induced polarization attenuation coating, when coating the unwelded battery surface, avoid the battery sheet welding position.

Images